House martin

Description

The house martin has a body length of about 13 cm and weights between 16 and 25 grams. It is thus smaller and slimmer than a sparrow and belongs to the medium-sized birds within the swallow family.

The head, back, upper side of the wings and tail of adult house martins are blue-black. The entire underparts of the body and the rump contrast with this with a pure white to floury white colouration. The short legs and feet are also white feathered. The toes and the few unfeathered parts of the legs are pale flesh-coloured. Compared to the barn swallow, the tail is less forked; strongly elongated outer feathers are absent. The eyes are brown; the beak is short and black. 

Occasionally, house martins also include whites whose plumage is either completely white or in which the white parts are much more extensive than in normally coloured house martins. The literature describes individuals in which only the head was normally coloured and the rest of the body was feathered in white, or in which only the right wing feathers, wing coverts and primaries were pure white.

Juveniles can be distinguished from adults by their brownish to brownish-black upperparts, which only shine bluish-black in some areas. The wings are also brownish and still lacking in lustre. The throat and flanks are grey feathered. The most striking distinguishing feature is the grey rump (pure white in adults). It has a speckled appearance as its dark brown feathers have white tips.

House martins are originally breeding birds that nest on vertical rock cliffs. Breeding colonies in such natural places still exist today. In its European range, however, the species is predominantly a synanthropic bird, using the open and populated cultural landscape as its habitat. Even in the European range, house martins still settle at high altitudes. In Austria, a colony of house martins has been documented on the Großglockner at an altitude of 2450 metres.

House martins depend on open areas with low vegetation. This enables them to hunt aerial plankton even when it flies low due to rainy or stormy weather. The proximity of larger bodies of water is also necessary to find suitable nesting material. There are different statements in the literature about how pronounced the cultural succession behaviour of the house martin is, especially in comparison to the barn swallow. High levels of air pollution may be responsible for house martins avoiding cities in some regions.

The text is a translation of an excerpt from Wikipedia (https://de.wikipedia.org/wiki/Mehlschwalbe). On wikipedia the text is available under a „Creative Commons Attribution/Share Alike“ licence. Status: 11 November 2021